The present invention relates to a collapsible baby stroller.
Attempts have been made to provide baby strollers of variable dimensions, which are conveniently carried in the manner of a walking stick even on buses or analogous transport means when in the maximum folding or collapsed position.
These strollers are formed by a number of mutually articulated tubular rod elements, which provide both the wheel supports, the handgrips and the seat attachments. A feature of these tubular elements is that their folding and unfolding movement is performed in a manner similar to the opening of a book or compass. In fact the articulated rod system of these strollers is such that substantially two groups of articulated rods are provided which in folded configuration are approximately coplanar. These coplanar groups of rods are arranged rotatable about an axis extending approximately breadthwise with respect to the overall extension of the stroller, so that a book like or compass like unfolding and folding may be obtained about the said axis. The said articulated rods are furthermore mutually interconnected so that their reciprocal distances vary with the degree of opening of the actual stroller. Transversely, that is width-wise, these types of strollers have the characteristic of expanding or narrowing through the action of diagonally arranged cross-pieces interconnecting in an articulated fashion the non-corresponding rods of the two sides. In other words the diagonal cross-pieces vary their reciprocal angles and can gain or lose transversely the space respectively lost or gained longitudinally because of the variations in the mutual positioning of said side tubes during the book-like opening or closing of the stroller.
Evidently such strollers require numerous component parts such as tubular elements and links and remarkable care in the study of the kinematic movements thereof. Moreover it is necessary to form a large number of articulations to interconnect the tubular elements. These articulations are costly and are in addition the cause of possible breakages and bindings. On the whole therefore the structure of these previous strollers are relatively complex and costly, as well as rather cumbersome. This last drawback is particularly annoying since manoeuvrability should be the basic characteristic of these strollers.
It should be observed that these previous strollers have a relatively short span between the sides when in a position of maximum opening, so that the baby seated therein is in a rather uncomfortable position. This drawback is a direct result of the above described structure, in that the maximum possible expansion of the strollers in a transversal sense is a characteristic depending directly on the overall dimensions of the actual stroller, the positions of complete opening and closure in a longitudinal sense being substantially constrained and unmodifiable, for reasons of encumbrance and ease of handling. The same applies in respect of the change of configuration in the transversal sense for the position of maximum closure. It therefore happens that in practice, since the stroller must not be too large and heavy, its maximum transverse dimension must be kept within narrow limits and in some cases insufficient.